Commit Graph

111 Commits

Author SHA1 Message Date
Paul Mundt
d5701647f1 serial: sh-sci: Generalize port pin initialization.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:44:43 +09:00
Paul Mundt
d830fa4584 serial: sh-sci: Tidy up fifo overrun error handling.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:44:43 +09:00
Paul Mundt
762c69e3ca serial: sh-sci: pr_debug() -> dev_dbg() conversion.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:44:43 +09:00
Paul Mundt
027e687249 serial: sh-sci: Fix up the cpufreq notifier to use the proper port clock.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:44:43 +09:00
Paul Mundt
07d2a1a1cd serial: sh-sci: Implement CONSOLE_POLL support and kill off old kgdb console.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:44:04 +09:00
Michael Trimarchi
e7c98dc76d serial: sh-sci: Codestyle cleanup patch.
Trivial coding style cleanups.

Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-12-22 18:42:52 +09:00
Paul Mundt
272966c070 serial: sh-sci: Reorder the SCxTDR write after the TDxE clear.
Under qemu there is a race between the TDxE read-and-clear and the SCxTDR
write. While on hardware it can be gauranteed that the read-and-clear
will happen prior to the character being written out, no such assumption
can be made under emulation. As this path happens with IRQs off and the
hardware itself doesn't care about the ordering, move the SCxTDR write
until after the read-and-clear.

Signed-off-by: Vladimir Prus <vladimir@codesourcery.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-11-13 17:46:06 +09:00
Yoshihiro Shimoda
1a22f08dbd serial: sh-sci: fix cannot work SH7723 SCIFA
SH7723 has SCIFA. This module is similer SCI register map, but it has FIFO.
So this patch adds new type(PORT_SCIFA) and change some type checking.

Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-11-12 12:29:56 +09:00
Michael Trimarchi
a8884e3415 sh: Fix up the shared IRQ demuxer's control bit testing logic.
Correct the interrupt handler in sh4 serial device, return the correct
value and check for what is anabled in the SCSCR register. The sh7722 is
broken just sending a break using minicom.

Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-31 16:10:23 +09:00
Paul Mundt
86d758ef2c Merge branches 'sh/serial-rework' and 'sh/oprofile' 2008-10-28 19:44:15 +09:00
Linus Torvalds
9301975ec2 Merge branch 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu
and x86/uv.

The sparseirq branch is just preliminary groundwork: no sparse IRQs are
actually implemented by this tree anymore - just the new APIs are added
while keeping the old way intact as well (the new APIs map 1:1 to
irq_desc[]).  The 'real' sparse IRQ support will then be a relatively
small patch ontop of this - with a v2.6.29 merge target.

* 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits)
  genirq: improve include files
  intr_remapping: fix typo
  io_apic: make irq_mis_count available on 64-bit too
  genirq: fix name space collisions of nr_irqs in arch/*
  genirq: fix name space collision of nr_irqs in autoprobe.c
  genirq: use iterators for irq_desc loops
  proc: fixup irq iterator
  genirq: add reverse iterator for irq_desc
  x86: move ack_bad_irq() to irq.c
  x86: unify show_interrupts() and proc helpers
  x86: cleanup show_interrupts
  genirq: cleanup the sparseirq modifications
  genirq: remove artifacts from sparseirq removal
  genirq: revert dynarray
  genirq: remove irq_to_desc_alloc
  genirq: remove sparse irq code
  genirq: use inline function for irq_to_desc
  genirq: consolidate nr_irqs and for_each_irq_desc()
  x86: remove sparse irq from Kconfig
  genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n
  ...
2008-10-20 13:23:01 -07:00
Yinghai Lu
a62c413373 drivers/serial: use nr_irqs
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:06 +02:00
Paul Mundt
15c73aaa44 serial: sh-sci: Kill off all of the SCI/SCIF special casing.
This was added at a time when the compiler did a less than stellar job of
optimizing out dead code. These days this tends to be less of a concern,
so kill it all off.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-02 19:47:12 +09:00
Paul Mundt
bc0f424faa Merge branch 'sh/g3-prep' 2008-10-02 19:14:11 +09:00
Paul Mundt
a2159b5221 serial: sh-sci: Dynamic clock management depends on HAVE_CLK.
Presently this is conditionalized on sh, and disabled for sh64.
Now that SH-5 ties in to the clock framework, the sh64 exception
can be dropped. Additionally, ARM will want to use the same hooks
once SH-Mobile G3 grows clock framework support, so switch these
paths over to HAVE_CLK now.

Once the H8 and ARM sh-sci users hook up HAVE_CLK, the driver can
be switched over to having an outright dependency on it and the
ifdefs can go away.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-02 19:09:13 +09:00
Paul Mundt
7ff731aeba serial: sh-sci: Handle the general UPF_IOREMAP case.
Presently we don't do much with UPF_IOREMAP other than special case it
for SH-5's onchip_remap() on the early console. Tie this in generically
for platforms that need the remap.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-01 15:46:58 +09:00
Paul Mundt
fa43972fab sh: fixup many sparse errors.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-09-08 10:35:04 +09:00
Nobuhiro Iwamatsu
c63847a362 sh: Add SCIF2 support for SH7763.
SH7763 has 3 SCIF device. Current code supports SCIF0 and 1.
SCIF0 and 1 are same register constitution, but only SCIF2 is different.
I added support of SCIF2.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-07-28 18:10:29 +09:00
Takashi Iwai
a88487c79b Fix compile errors in SGI console drivers (linux-next tree)
The below is the patch to replace blindly all possible places,
including Jack's fixes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
(Reviewed and checked rather than blindly added)
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:36 -07:00
Harvey Harrison
bfd3c7a728 sh: use the common ascii hex helpers
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-05-16 15:09:08 +09:00
Magnus Damm
346b746300 sh-sci: improve sh7722 support
Improve sh7722 support for SCIF1 and SCIF2 and separate code
from sh7366 implementation.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-05-08 19:51:57 +09:00
Paul Mundt
85f094ecb1 sh: Enable use of the clk fwk on SH-5.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-05-08 19:51:42 +09:00
Harvey Harrison
71cc2c2152 serial: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:54 -07:00
Paul Mundt
178dd0cd28 sh: Add support for SH7723 CPU subtype.
This adds basic support for the SH7723 MobileR2 CPU.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-04-18 09:50:07 -07:00
Kay Sievers
e169c13964 serial: fix platform driver hotplug/coldplug
Since 43cc71eed1, the platform modalias is
prefixed with "platform:".  Add MODULE_ALIAS() to the hotpluggable serial
platform drivers, to re-enable auto loading.

NOTE that Kconfig for some of these drivers doesn't allow modular builds, and
thus doesn't match the driver source's unload support.  Presumably their
unload code is buggy and/or weakly tested...

[dbrownell@users.sourceforge.net: more drivers, registration fixes]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-15 19:35:40 -07:00
Yutaro Ebihara
cae167d3d7 serial: sh-sci: Fix fifo stall on SH7760/SH7780/SH7785 SCIF.
There was an off-by-1 in the SCRFDR calculation that caused writes over
128-bytes to hang in the FIFO. Fix it up.

Signed-off-by: Yutaro Ebihara <ebiharaml@si-linux.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-03-11 13:58:50 +09:00
Paul Mundt
96de1a8f02 serial: Move asm-sh/sci.h to linux/serial_sci.h.
This header is needed on other architectures as well (namely h8300),
which currently fails to build without this in place. Rather than
duplicating the port definition completely there, just move this to a
common location instead.

This should get h8300 working again for 2.6.25, in addition to the
changes already pushed by Sato-san in -rc2.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-02-26 14:52:45 +09:00
Magnus Damm
9109a30e5a sh: add support for sh7366 processor
This patch adds sh7366 cpu supports. Just the most basic things like interrupt
controller, clocks and serial port are included at this point.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-02-14 14:22:10 +09:00
Yoshihiro Shimoda
7d740a066f sh: Add support for SH7763 CPU subtype.
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28 13:19:02 +09:00
Yoshihiro Shimoda
31a49c4bf8 sh: Add support for SH7721 CPU subtype.
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28 13:19:02 +09:00
Paul Mundt
68362e0857 serial: sh-sci: kgdb console build fixes.
The kgdb console code requires uart_set_options() and friends, which
are only provided by the serial core when console support is enabled.
These were sitting under CONFIG_SH_KGDB and resulted in a link error
when console support wasn't enabled, work that by rolling the console
routines under CONFIG_SH_KGDB_CONSOLE, which they should have been
all along.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-09-21 11:57:53 +09:00
Markus Brunner
3ea6bc3de4 sh: Add SH7720 CPU support.
This adds support for the SH7720 (SH3-DSP) CPU.

Signed-off by: Markus Brunner <super.firetwister@gmail.com>
Signed-off by: Mark Jonas <toertel@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-09-21 11:57:49 +09:00
Paul Mundt
e289fd972c serial: sh-sci: Tidy cpufreq printk.
This was a bit more verbose than it needed to be.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-09-21 11:57:49 +09:00
Magnus Damm
d89ddd1c84 sh: remove support for sh7300 and solution engine 7300
This patch removes old dead code:
- kill off sh7300 cpu support
- get rid of broken solution engine 7300 board support

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-26 15:37:57 +09:00
Paul Mundt
2b1bd1ac5d sh: Preliminary support for the SH-X3 CPU.
This adds basic support for UP SH-X3.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-06-20 18:27:10 +09:00
Paul Mundt
005a336e71 serial: sh-sci: Fix module clock refcount for serial console.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:11:56 +00:00
dmitry pervushin
1534a3b3dc serial: sh-sci: Fix module clock refcounting.
This adds the enable/disable hooks for the port clock to sh-sci.

Signed-off-by: dmitry pervushin <dimka@nomadgs.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:11:56 +00:00
Nobuhiro Iwamatsu
9465a54fa4 sh: MS7712SE01 board support.
Support the SH7712 (SH3-DSP) Solution Engine reference board.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:10:54 +00:00
Paul Mundt
8248daac6b serial: sh-sci: Kill off breakpoint in break IRQ.
With the GDB stub being entered via a special sysrq trigger,
we don't want to hit it directly from sci_br_interrupt().
Without this, there is access to the other sysrq triggers when
kgdb is enabled.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:10:53 +00:00
Paul Mundt
32351a28a7 sh: Add SH7785 Highlander board support (R7785RP).
This adds preliminary support for the SH7785-based Highlander board.
Some of the Highlander support code is reordered so that most of it
can be reused directly.

This also plugs in missing SH7785 checks in the places that need it,
as this is the first board to support the CPU.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:10:53 +00:00
Paul Mundt
fa5da2f7bd sh: Bring kgdb back from the dead.
This code has suffered quite a bit of bitrot, do some basic
tidying to get it to a reasonably functional state again.
This gets the basic support and the console working again.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-07 02:10:51 +00:00
Paul Mundt
0b3d4ef6fe serial: Fix sh-sci break interrupt/sysrq handling.
The sh-sci sci_br_interrupt() handler was failing to call
in to uart_handle_break(), which was something that only
the SH-3 path was doing, fix that up.

Additionally, SUPPORT_SYSRQ seems to have moved down too
far, move it back to the top so uart_handle_break() and
friends aren't no-ops.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-03-14 13:22:37 +09:00
Paul Mundt
41504c3972 sh: SH-MobileR SH7722 CPU support.
This adds CPU support for the SH7722.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-12-12 08:42:09 +09:00
Alan Cox
606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
Paul Mundt
1d118562c2 sh: Clock framework tidying.
This syncs up the SH clock framework with the linux/clk.h API,
for which there were only some minor changes required, namely
the clk_get() dev_id and subsequent callsites.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-12-06 10:45:40 +09:00
Paul Mundt
35f3c5185b sh: Updates for IRQ handler changes.
Trivial fixes for build breakage introduced by IRQ handler changes.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-10-06 15:31:16 +09:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Dave Jones
038b0a6d8d Remove all inclusions of <linux/config.h>
kbuild explicitly includes this at build time.

Signed-off-by: Dave Jones <davej@redhat.com>
2006-10-04 03:38:54 -04:00
Paul Mundt
e108b2ca23 serial: Rework sh-sci for driver model.
sh-sci was turning in to an unmaintainable mess, especially with
regards to the port list. This cleans it up quite a bit, and
switches over to a platform device model where subtypes will
register their port list individually in their setup code.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-09-27 16:32:13 +09:00
Paul Mundt
21264136ce sh64: Trivial build fixes.
While we've been sorting out the toolchain fiasco, some of
the code has suffered a bit of bitrot. Building with GCC4
also brings up some more build warnings. Trivial fixes for
both issues.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-09-12 14:36:46 +09:00
Thomas Gleixner
40663cc7f1 [PATCH] irq-flags: serial: Use the new IRQF_ constants
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:53 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Greg Kroah-Hartman
aa4148cfc7 [PATCH] devfs: Remove devfs support from the serial subsystem
Also fixes all serial drivers.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:05 -07:00
Russell King
59a675b220 [SERIAL] uart_port flags member should use UPF_*
Convert usage of ASYNC_* to UPF_*.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-05 10:52:29 +00:00
Russell King
9b4a161777 [SERIAL] uart_port iotype member should use UPIO_*
Convert usage of SERIAL_IO_* to UPIO_*.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-05 10:48:10 +00:00
Paul Mundt
b7a76e4b4e [PATCH] sh: sh-sci clock framework updates
A couple of updates for the sh-sci serial driver:

	- Update for clock framework on sh.
	- Fix a compile error introduced by some h8300 changes.
	- Add SH7770/SH7780 subtype support.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:20 -08:00
Russell King
ce8337cb7d [SERIAL] Don't use ASYNC_ constants with the uart_port structure
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-21 19:28:15 +00:00
Alan Cox
33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Yoshinori Sato
d656901bca [PATCH] sh-sci.c sci_start_tx error
Argument does not agree.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-14 17:10:13 -07:00
Russell King
b129a8ccd5 [SERIAL] Clean up and fix tty transmission start/stoping
The start_tx and stop_tx methods were passed a flag to indicate
whether the start/stop was from the tty start/stop callbacks, and
some drivers used this flag to decide whether to ask the UART to
immediately stop transmission (where the UART supports such a
feature.)

There are other cases when we wish this to occur - when CTS is
lowered, or if we change from soft to hard flow control and CTS
is inactive.  In these cases, this flag was false, and we would
allow the transmitter to drain before stopping.

There is really only one case where we want to let the transmitter
drain before disabling, and that's when we run out of characters
to send.

Hence, re-jig the start_tx and stop_tx methods to eliminate this
flag, and introduce new functions for the special "disable and
allow transmitter to drain" case.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-31 10:12:14 +01:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00